Price Channel

As stated in Robert W. Colby and Thomas A. Meyers's The Encyclopedia of Technical Market Indicators
(New York: Irwin, 1988), Steven L. Kille has this to say about the Price Channel indicator:

"Price Channel is one of the simplest and oldest trend-following models. It requires no calculations.
The rules are: Buy when the weekly closing price moves up to a new 20-period high; sell and sell short when
the weekly closing price moves down to a new 20-period low. In other words, when price moves out of its
n-period range, go in the direction of this new trend." (p. 392)